Effect of Oral Strips Containing Essential Oils on Oral Microbiota

Objective: The aim of this study was to evaluate the antimicrobial effect of oral strips containing essential oils on different species of the oral microbiota. Methods: Saliva samples were collected from 20 subjects with oral health, diluted and placed onto blood agar. The subjects were asked to place the strip (Listerine PocketPaks^TM) on the tongue allowing it to dissolve. After 30 min, new saliva samples were collected and prepared as described before. The plates with the cultures were incubated in anaerobiosis at 37^oC for 7 days. Colony counts (CFU/mL) were determined for each sample. The plates were washed with 1mL of TE buffer and the bacterial suspensions were processed for the identification of 25 species by DNA probes and the Checkerboard DNA-DNA hybridization method. Differences in the prevalence and the level of the species were determined by Wilcoxon sign rank and Chi-square tests. Results: No significant differences in the CFUs of the total saliva were observed (p=0.286). The majority of the species were reduced in prevalence and levels, including the pathogens A. actinomycetemcomitans (p=0.003), C. rectus (p=0.051), P. gingivalis (p=0.001), Fusobacterium spp. (p=0.003), T. forsythensis (p=0.371). Conversely, the beneficial species V. parvula (p=0.001), Actinomyces spp. (p=0.005) and S. gordonii (p=0.003) showed a significant increase after the use of the strips. Conclusions: The use of the oral strips containing essential oils resulted in a small decrease in the total numbers of salivary microorganisms. However, a significant decrease of periodontopathogens and an increase in species compatible with health is observed.